All of the above.
Resistance, if I could only pick one.
I would play the hell out of a good Socom reboot but I just don't trust Sony to make a Socom game that isn't a bastardized mess. I'd rather it stay dead than come back with clown costumes, pink mohawks, neon guns, etc. etc. I get that these games need to make money but I'd rather just keep my memories of Socom intact and not tarnish them any more than Socom 4 managed to. A true return to form would be incredible but I just don't see who would develop it or how they could monetize it without ruining it.
Killzone is cool but Killzone 3 and Shadow Fall were just okay. If they did bring it back, I would like to see a return to the ideas that the original game had. It wasn't perfect but it was definitely the most unique of them all. Obviously Killzone 2 was awesome but I don't think a retread of that game would be all that exciting these days.
Resistance has so much potential. The alternate history approach is awesome, the chimera are well designed, and the weapons are ridiculously fun to use. I would definitely be the most optimistic about a reboot of this franchise. The multiplayer in the first game was super underrated too. Easily one of the best Halo-like multiplayer modes that I've played.